Used to work in Gardner in the 80s, -I visited the Quabbin lots of times, but haven't been there in probably 15 years. I did visit the F-94 jet crash site. IIRC, it's a left at the fork out of Dana Center, further than that I don't remember the details. There are sites that have the coordinates. I found it the old-fashioned way using a map that someone put a dot on.
I can't post URLs or photos yet, but google "F-94 Quabbin"- there are several articles about the crash.